The object of the present invention is a data processing system with interconnection between its central unit and its peripheral units. Current data processing systems consist of central units, processors or central processing units (CPUs) and a central memory consisting of one or several memory units (MMUs), and one or several input/output controllers that permit communication with peripheral units, for example, disk storage, modems, printers, etc. The processors (CPUs) and the central memory units (MMUs) communicate via an internal communication bus in which the protocol is chosen by the host system designer as a function of its architecture. Most often, these protocols are specific and quite varied. In industrial use, on the other hand, bus standards are often seen, such as the IEEE standard "basket base" buses. The most common of these standard buses present at least one parallel communication channel.
The goal of the present invention is a data processing system in which the interconnection assures the interface between buses with different protocols, in a flexible way in order to adapt the internal bus to the system host and in an efficient manner to use the standard buses best in terms of speed, cost and flexibility.
To this end, the invention proposes a data processing system consisting of at least one central unit (CPU) and one central memory (MMU), communicating via an internal communication bus, at least one peripheral unit linked with a control module, hereinafter called IOM module, and at least one interconnection between the IOM module and the internal bus, the system being characterized by the fact that a part of the IOM module is connected to an external communication bus of a different kind than the internal bus and that on the other hand, the interconnection consists of an internal interface device (CLM) connected to the internal bus, an external interface device (PLM) connected to the external bus, an inter-device interface, hereinafter called PLI interface, located between the above-mentioned interface devices (CLM) (PLM), assuring adaptation between the protocols used respectively in the two buses and the PLI interface.